1. Field of the Invention
The invention relates to double deck connector assemblies, and particularly to the connector including the housing defining upper and lower ports each with a pair of latch devices aside for retaining therein the corresponding module wherein the main body of the upper port and that of the lower port are vertically aligned with a minimum offset in a front-to-back direction.
2. The Related Art
As known, till now most double-deck SO DIMM (Dual Inline Memory Module) or Mini SIMM (Single Inline Memory Module) connectors generally require a relatively significant offset between the upper connection port and the lower connection port in a front-to-back direction, or require a relatively significant distance or gap between the upper connection port and the lower connection port in a vertical direction, whereby the lower module, which is ready to be inserted into the lower connection port, is able to approach the lower connection portion at an angle with its upper surface substantially positioned below the latching lug of the upper latch for avoiding improper interference between the lower module and the latching lug of the upper latch during downward rotation of the lower module for reaching its final horizontal final fixed position. U.S. Pat. Nos. 5,697,802 (FIGS. 6, 7), 5,641,295 (FIG. 3), 5,993,234, and 5,755,585 (the grand parent application of the invention) generally disclose this character. Anyhow, only U.S. Pat. No. 5,833,478 (the '478 patent which is the great grand parent application of the invention with the same assignee) show the vertically aligned upper and lower connection ports without any offset thereof, and the lower module may pass over the latching lug of the upper latch aside for approaching and engaging the lower latch. According to the main figure of the '478 patent, because the imperfect interengagement/interrelationship between the latching lug of the upper latch and the notch of the lower module, the notch is essentially formed to be relatively much larger than the standard size for avoiding any improper interference with the latching lug of the upper latch. Under this situation, the structure disclosed in the '478 patent may not be fully acceptable in the industry.
Therefore, an object of the invention is to provide a double-deck SO DIMM connector assembly including a housing defining upper and lower ports, wherein the position and the contour of the latching lug of the upper latch have been properly and precisely configured so as to allow the lower level module to be easily inserted into the lower connection port without interference therewith under the condition of relatively little offset arrangement of the upper connection port and the lower connection port in the front-to-back direction of the connector assembly.
Another object of the invention is to provide two-step withdrawal of the lower level module wherein the lower level module is first released by deflection of the latching lug of the lower latch while still being retained by the latching lug of the upper latch, and then successively fully released by deflection of the latching lug of the upper latch.